Description:TECHNICAL FIELD
[001] The present disclosure generally relates to Power Take-Off (PTO) systems in vehicles, and more particularly, relates to a method and a locking mechanism for smooth PTO operation in vehicle, by establishing a sequence of operations.
BACKGROUND
[002] Agricultural vehicles such as tractors includes a Power Take-Off (PTO) system that transfers an engine’s mechanical power to another piece of equipment connected through a PTO shaft to the vehicle. Farm equipment such as thresher, rotavator, cultivator, reaper, etc. which require high torque to operate are connected to the vehicle through the PTO shaft, wherein the PTO system transmits the required torque to operate the equipment.
[003] Conventionally, the PTO shaft of the tractor is engaged and disengaged by actuating a lever. In an Independent Power Take-Off (IPTO) system two levers viz. SLIPTO and CRPTO are used to acuate the PTO. The SLIPTO lever is used to allow/start or stop the power flow from flywheel of the vehicle to the PTO shaft. Whereas the CRPTO lever is used to obtain PTO speed at different gear ratios. Therefore, for the smooth operation of the PTO, a three-step sequence is required to be followed. First, the SLIPTO lever needs to be actuated to stop the power flow from flywheel to PTO shaft. Second, the CRPTO lever needs to be actuated to set the gear ratio for desired PTO speed, and third, the SLIPTO lever is required to be actuated back to its initial position to start the power flow from flywheel to PTO shaft. Failing to follow abovementioned procedure in the IPTO system, results in wear and tear of the gear teeth of the PTO system, and thereby reducing the gear life.
[004] Further, if the vehicle is used in different kinds of soil conditions, different kind of resistance force is induced on it. In certain type of operations such as when a Reaper is connected to a tractor for carrying out agricultural operations, a higher magnitude of force is induced. This induced force tries to actuate the coupler such that the PTO gets disengaged or leads to partial engagement. Due to partial engagement or disengagement, smooth operation of PTO is hampered and may even lead to wearing of the gear teeth.
[005] The present solutions include providing a locking mechanism with the lever at a fixed position. But due to dimensional variation of parts arising due to manufacturing constraints, lock with fixed position may lead to partial engagement in some cases.
[006] Therefore, there exists a need for a method and locking mechanism for smooth PTO operation in vehicle, by establishing a sequence of operations, which obviates the aforementioned drawbacks.
OBJECTS
[007] The principal object of an embodiment of this invention is to provide a locking mechanism for smooth PTO operation in vehicle such as tractor, by establishing a sequence of operations.
[008] Another object of an embodiment of this invention is to provide a foolproof mechanism to reduce gear teeth wear and tear by establishing a sequence of operations with the locking mechanism in heavy vehicles such as tractor, whereby the set of sequence of operation helps to significantly reduce wear and tear of engaging gear teeth because PTO speed shifting (by actuating CRPTO Lever) is allowed only when PTO clutch is disengaged from flywheel.
[009] Another object of an embodiment of this invention is to provide the locking mechanism with adjustable mounting length which facilitates in accommodating a dimensional variation in the actuating/ selection lever of the IPTO system.
[010] Still another object of an embodiment of this invention is to provide the locking mechanism for the independent PTO lever assembly which eliminates operational breakdown of the PTO, provides smooth PTO operation without accidental disengagement, and is easy to assemble on tractors and other vehicles.
[011] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[012] The embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[013] Fig. 1 is a perspective top view of a locking mechanism for IPTO lever assembly, according to an embodiment of the invention as disclosed herein;
[014] Fig. 2 is an exploded view of the locking mechanism for the IPTO lever assembly, according to an embodiment of the invention as disclosed herein;
[015] Figs 3a and 3b depict a perspective view of the locking mechanism for the IPTO lever assembly, according to an embodiment of the invention as disclosed herein;
[016] Fig. 4a depicts a top view of the locking mechanism, wherein a CRPTO lever (202) and a SLIPTO lever (201) of the ITPO lever assembly are in respective original positions, according to an embodiment of the invention as disclosed herein;
[017] Fig. 4b depicts a top view of the locking mechanism, wherein the CRPTO lever (202) is in an initial original position and the SLIPTO lever (201) is in the final position, according to an embodiment of the invention as disclosed herein;
[018] Fig. 4c is a top view of the locking mechanism, wherein the CRPTO lever (202) is in a final position and the SLIPTO lever (201) is in the final position, according to an embodiment of the invention as disclosed herein; and
[019] Fig. 4d is a top view of the locking mechanism, wherein the CRPTO lever (202) is locked in the final position and the SLIPTO lever (201) is in the original position, according to an embodiment of the invention as disclosed herein.
DETAILED DESCRIPTION
[020] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[021] The embodiments herein achieve a locking mechanism for smooth PTO operation in vehicle such as tractor, by establishing a sequence of operations. Further, the embodiments herein achieve a foolproof mechanism to reduce gear teeth wear and tear by establishing a sequence of operations with the locking mechanism in heavy vehicles such as tractor, whereby the set of sequence of operation helps to significantly reduce wear and tear of engaging gear teeth because PTO speed shifting (by actuating CRPTO Lever) is allowed only when PTO clutch is disengaged from flywheel. Furthermore, the embodiments herein achieve the locking mechanism with adjustable mounting length which facilitates in accommodating a dimensional variation in the actuating/ selection lever of the IPTO system and its mating parts. Furthermore, the embodiments herein achieve the locking mechanism for the independent PTO lever assembly which eliminates operational breakdown of the PTO, provides smooth PTO operation without accidental disengagement, and is easy to assemble on tractors and other vehicles. Also, the embodiments herein achieve a method for smooth PTO operation in vehicle such as tractor, by establishing a sequence of operations. Referring now to the drawing, and more particularly to Fig. 1 through Fig. 4, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[022] Typically, an independent power take-off system (IPTO) is mechanically actuated through a plurality of lever assemblies. This lever assembly comprises of two levers: a first lever called as a CRPTO lever, and a second lever called as a SLIPTO lever. The SLIPTO lever is provided to start and stop the power supply to the PTO (or PTO shaft), wherein SLIPTO lever starts or stops the power flow from flywheel of the vehicle to the PTO shaft. The CRPTO lever is provided to select PTO speed at different gear ratios.
[023] The standard operation of the IPTO system includes actuating the SLIPTO lever to stop the power flow from the flywheel to the PTO shaft, and actuating the CRPTO lever to set the gear ratio for desired PTO speed and actuating the SLIPTO lever to start the power flow from the flywheel to the PTO shaft.
[024] Fig. 3a shows the IPTO lever assembly (200) comprising the CRPTO lever (202) and the SLIPTO lever (201), wherein the SLIPTO lever (201) is in a second position (SP) and the CRPTO lever (202) is in its beginning position (BP), according to an embodiment of the invention as disclosed herein. Fig. 3b depicts the IPTO lever assembly (200), wherein the CRPTO lever (202) is in a terminal position (TP) and the SLIPTO lever (201) is actuated back to the first position (FP), according to an embodiment of the invention as disclosed herein.
[025] Fig. 1 depicts is a top view of the locking mechanism (100) for the IPTO lever assembly (200) in a vehicle, according to an embodiment of the invention as disclosed herein. The locking mechanism (100) comprises a base plate (101), a pivot lever (102) mounted on the pivot pin (103) at a predetermined position, a pivot pin (103) fixedly attached to the base plate (101) at a predetermined position, a movable locking pin (104) mounted on the pivot lever (102) at a predetermined position, a guide bracket (105) mounted on the base plate (101), and a spring (106).
[026] The locking mechanism (100) includes the base plate (101) which forms the platform for holding the locking mechanism (100). The base plate (101) is mounted at a predetermined position in the vehicle. Further, the locking mechanism (100) includes the pivot pin (103) which includes one end affixed to the base plate (101). Further, the other end of the pivot pin (103) is configured to receive the pivot lever (102). In an embodiment, the pivot pin (103) is at least a stepped cylindrical member.
[027] Further, the locking mechanism (100) includes the pivot lever (102) which is provided such that the SLIPTO lever (201) operatively engages with the pivot lever (102), so that the pivot lever (102) is rotated in a predetermined direction when the SLIPTO lever (201) is actuated from the first position (FP) to the second position (SP), and rotated in an opposite direction to the predetermined direction when the SLIPTO lever (201) is actuated back to the first position (FP).
[028] Furthermore, the locking mechanism (100) includes the locking pin (104) which is configured to retract when the pivot lever (102) rotates in the predetermined direction, when the SLIPTO lever (201) is actuated to the second position (SP). And the locking pin (104) is configured to extend, when pivot lever (102) rotates in the opposite direction, when the SLIPTO lever (201) is actuated back to the first position (FP).
[029] According to an embodiment of the invention as shown in Fig. 2, the locking mechanism (100) further comprises a circlip (109) connected to the pivot lever (102) at an upper portion of said pivot lever (102). The circlip is provided in the locking mechanism so that the pivot lever (102) is held attached to the pivot pin (103). Further, the locking mechanism (100) includes at least one first washer (108) which disposed below the circlip (109) at the upper portion of the pivot lever (102). Furthermore, the locking mechanism (100) includes at least one second washer (110) which is mounted on the pin of pivot lever (102). The locking mechanism (100) further includes a split pin (111) which is disposed on the pivot lever (102) such that the pivot lever (102) is securely connected to the locking pin (104) through the second washer (110) and split pin (111).
[030] The locking mechanism (100) includes a spring mounting bracket (107) which is integrated to the base plate (101) at a predetermined position. A first end of the spring (106) is connected to the spring mounting bracket (107) and a second end of the spring (106) is connected to the locking pin (104) as shown in Fig. 1.
[031] The locking mechanism (100) is configured to lock the CRPTO lever (202) in its beginning position (BP) to prevent engagement for PTO operation at flywheel speed and terminal position (TP) to prevent disengagement or partial engagement of the PTO. As shown in Fig. 4a, the CRPTO lever (202) is in its beginning position (BP) and the SLIPTO lever (201) is also in its first position (FP). Further, the pivot lever (102) is in its initial position wherein it is engaged with the SLIPTO lever (201). The locking pin (104) is also in its initial position, wherein it extends outwards of the base plate (101) to the predetermined length. In this initial condition of the locking mechanism (100), the spring (106) exerts a force on the pivot lever (102) and the locking pin (104) to retain the pivot lever (102) in an original position. When the SLIPTO lever (201) is actuated to the second position (SP), as shown in Fig. 4b, it generates a torque on the pivot lever (102), opposite to the torque generated due to the force of the spring (106) and results in rotation of the pivot lever (102) in clockwise direction. The rotation of the pivot lever (102) causes the locking pin (104) to retract backwards towards the base plate (101), therefore allowing the free movement of the CRPTO lever (202). When the locking pin (104) retracts, the CRPTO lever (202) is moved to terminal position (TP) (as shown in Fig. 4c).
[032] After the CRPTO lever (202) is moved to the terminal position (TP), the SLIPTO lever (201) is actuated to the first position (FP) to enable power supply to the PTO of the vehicle. When the SLIPTO lever (201) is actuated to the first position (FP), (as shown in Fig. 4d), since there is no torque acting against the spring force generated torque, the pivot lever (102) is released from its rotated position, whereby the pivot lever (102) rotates back in an opposite direction (anti-clockwise direction) to its original position and causes the locking pin (104) to extend to its original position. The extension of the locking pin (104) to its initial position, results in the blocking of movement of the CRPTO lever (202), therefore locking the IPTO lever assembly in the required position. The locking mechanism (100) ensures that the CRPTO lever (202) and SLIPTO lever (201) are actuated in the correct sequence, therefore aiding in the smooth operation of the PTO and preventing the wearing of gear teeth of the PTO shaft. Further, locking of the CRPTO lever (202) ensures that there is no disengagement or partial engagement of the PTO, especially when an equipment attached to the vehicle through the PTO is used in difficult terrains and soil conditions. The locking mechanism (100) is configured to have adjustable mounting length which helps in accommodating the dimensional variation in the actuating/ selection levers of the IPTO system and its mating parts.
[033] The technical advantages achieved by the embodiments disclosed herein include smooth PTO shifting, less wear and tear of gear teeth, elimination of operational breakdown, small and portable assembly for easy fitment.
[034] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
, Claims:We claim,
1. A locking mechanism (100) for locking an PTO lever (or CRPTO lever) (202) of a vehicle, comprising:
a pivot pin (103) mounted on a base plate (101), said pivot pin (103) engaged to a pivot lever (102), said pivot lever (102) adapted to rotate about an axis of said pivot pin (103) upon actuation by a SLIPTO lever (201);
a locking pin (104) connected to said pivot lever (102), said locking pin (104) adapted to move between an extended position and a retracted position relative to said base plate (101), when actuated by rotation of said pivot lever (102); and
a spring (106) connected between said locking pin (104) and a spring mounting bracket (107) defined on said base plate (101).

2. The locking mechanism (100) as claimed in claim 1, wherein said pivot lever (102) rotates in a predetermined direction, when said SLIPTO lever (201) is actuated from a first position (FP) to a second position (SP), said locking pin (104) adapted to move to said retracted position, when said pivot lever (102) is actuated by said movement of said SLIPTO lever (201) from said first position (FP) to said second position (SP), and said locking pin (104) adapted to move to said extended position, when said pivot lever (102) is actuated by said movement of said SLIPTO lever (201) from said second position (SP) to said first position (FP).

3. The locking mechanism (100) as claimed in claim 1, wherein said pivot pin (103) is fixedly attached to said base plate (101) at one end at a predetermined position, said pivot pin (103) is adapted to receive said pivot lever (102) at the other end, said pivot pin (103) extends orthogonally in an upward direction for a predetermined height.

4. The locking mechanism (100) as claimed in claim 1, wherein said locking mechanism (100) includes a guide bracket (105) mounted at a predetermined position of said base plate (101), said guide bracket (105) configured to guide and limit a side-ward movement of said locking pin (104) when actuated by said pivot lever (102).

5. The locking mechanism (100) as claimed in claim 1, wherein said spring (106) is configured to pull said pivot lever (102) through said locking pin (104) to said first position (FP) when said SLIPTO lever (201) is moved from said second position (SP) to said first position (FP).

6. The locking mechanism (100) as claimed in claim 1, wherein said locking pin (104) is configured to retract to said predetermined position so that said CRPTO lever (202) is moved from an beginning position (BP) to a terminal position (TP); and
extend to said predetermined position from said retracted position to lock/block said CRPTO lever (202) in said terminal position (TP), when said SLIPTO lever (201) is actuated from said second position (SP) to said first position (FP).

7. The locking mechanism (100) as claimed in claim 1, wherein said locking mechanism (100) includes:
a circlip (109) connected to said pivot lever (102) at an upper portion of said pivot lever (102); and
a first washer (108) disposed below said circlip (109) at said upper portion of said pivot lever (102).

8. The locking mechanism (100) as claimed in claim 1, wherein said locking mechanism (100) includes:
said pivot lever (102);
a split pin (111) connected to said pivot lever (102) and said pivot pin (103), such that said split pin (111) secures locking pin (104) with said pivot lever (102) so that said locking pin (104) moves according to the movement of said pivot lever (102); and
at least one second washer (110) disposed between said locking pin (104) and said split pin (111).

9. The locking mechanism (100) as claimed in claim 1, wherein said locking mechanism (100) includes said spring mounting bracket (107) integrated to said base plate (101) at a predetermined position, wherein a first end of said spring (106) is connected to said spring mounting bracket (107) and a second end of said spring (106) is connected to said locking pin (104) at a predetermined position.